Answer: Respiration inhales oxygen gases and exhales carbon dioxide.
Explanation: Here, Oxygen enters the blood during inhalation, and carbon dioxide leaves during exhalation. This process is called Respiration. Air enters through the nose or mouth and goes through the nostrils, then the pharynx where two tubes are seen one for food and the other for air. From there it goes to the larynx, the voice box. Next air travels to the trachea(the windpipe) from which they get divided into left and right air tubes called bronchi. Smaller bronchi are called bronchioles. These end in tiny air sacs called alveoli. Exchange of gases takes place and revert back.